The present invention relates to a connecting element, particularly for windows, doors and the like, and a method of manufacturing the same.
Methods of manufacturing a connecting element have been proposed in the art, in accordance with which two elongated profiled elements are provided spaced from one another in a first direction transverse to the direction of elongation thereof so as to bound with one another a channel which is open at at least one side thereof, supplying into the channel a hardenable heat insulating material so as to fill the same, and hardening the heat insulating material in this channel. The thusmanufactured connecting element includes two elongated profiled elements and an insulating insert which connects the profiled elements with one another.
One of such methods is disclosed in the German Auslegeschrift No. 1,245,567. In accordance with this method an integral member is provided, which includes two such elongated profiled elements connected with one another by a connecting portion which forms a bottom of this integral member. A heat insulating sealing material is supplied into a channel formed between the profiled elements and the connecting portion, and after the material is hardened, the connecting portion is mechanically removed, for instance by milling, so that the metallic profiled elements are no longer connected by metallic means.
In accordance with a method disclosed in the German Offenlegungsschrift No. 2,129,964, two separate elongated metallic profiled elements are provided which are positioned relative to one another so as to bound the above-mentioned channel, and an additional bottom member is provided so as to bound this channel from below. The channel which is bounded by the separate metallic profiled elements and the bottom member is thereupon filled by the heat insulating material, and after hardening of the latter the bottom member is removed. It is understood that the bottom member serves for bounding the channel and supporting the heat insulating material supplied therein.
It has been known from the practice to provide holding means in the metallic profiled elements, such as projections or undercuts, and to provide projections on outer edges of the above-mentioned bottom member so that the latter can be inserted or clamped in the holding means before supplying the heat insulating material into the channel. An advantage of such a method is that the bottom or supporting member which is constituted by a material having low heat conduction characteristics can remain between the metallic profiled elements after hardening of the insulating material, inasmuch as heat insulating properties of this member do not undesirably affect heat insulation between the metallic profiled elements.
In all the above-discussed methods, the heat insulating material completely fills the channel which is bound between the metallic profiled elements. Measurements which have been performed for estimating the heat transmission between the metallic profiled elements of the connecting element manufactured in accordance with the above-mentioned methods, have shown that the attained magnitude of heat conduction has not always corresponded to the required standards. For these reasons, up to now from a great number of materials only some insulating materials could be utilized which satisfy both the requirements made with respect to their heat insulating characteristics, and the requirements made with respect to their strength. Thus, the selection of an insulating material for such connecting elements had to be made on a compromise. For instance, a material which is extremely inexpensive, has outstanding strength, has good filling properties and short hardening time, cannot be used until it has such heat conduction characteristics that when the connecting element is manufactured the heat insulating insert produced by such a material will satisfy the required standards.